1. Field of the Invention
The present invention generally relates to an electronic component, a substrate-type terminal included therein, and an electronic component mounted structure, and particularly to an electronic component to which alternating current (ac) voltage is applied, a substrate-type terminal included therein, and an electronic component mounted structure.
2. Description of the Related Art
In recent years, electronic devices are rapidly enhanced in performance, and accordingly, multilayer ceramic capacitors are increased in capacitance. A large capacitance multilayer ceramic capacitor includes a dielectric formed of material including barium titanate or similar, high dielectric constant ceramics.
These high dielectric constant ceramics have piezoelectricity and electrostrictivity. As such, when voltage is applied to the multilayer ceramic capacitor including a dielectric formed of a high dielectric constant ceramic, the multilayer ceramic capacitor is mechanically strained.
As such, when ac voltage or direct current (dc) voltage with an ac component superimposed thereon is applied to these multilayer ceramic capacitors, they are mechanically strained and accordingly oscillate. This oscillation propagates to an external circuit board having the multilayer ceramic capacitor connected thereto.
When the propagated oscillation causes the external circuit board to oscillate in an audio frequency range of 20 Hz to 20 kHz, the external circuit board causes an audible sound generally referred to as “acoustic noise”.
Electronic components having structures to reduce this acoustic noise are disclosed in prior art documents including Japanese Patent Laying-Open No. 2004-134430 and WO 2012/090986.
Japanese Patent Laying-Open No. 2004-134430 describes an electronic component with a multilayer capacitor having a body, or a capacitor element, overlying a single interposer board. The interposer board has a front surface with a pair of mounting electrodes disposed thereon and connected to a pair of external electrodes, respectively, of the capacitor element. The interposer board has a back surface with a pair of connecting electrodes disposed thereon and soldered to line patterns, respectively, of a substrate.
The pair of mounting electrodes and the pair of connecting electrodes are disposed on the interposer board such that the pairs are connected by virtual straight lines extending in perpendicular or substantially perpendicular directions, respectively.
WO 2012/090986 describes an electronic component with an interposer including an insulating substrate having one major surface to mount a multilayer ceramic capacitor thereon, the major surface having mounting electrodes. The insulating substrate, as observed in a direction perpendicular or substantially perpendicular to the major surface, is generally identical in geometry to the multilayer ceramic capacitor to be mounted. The multilayer ceramic capacitor is mounted on the insulating substrate such that they have their respective longitudinal directions generally matching each other.
The insulating substrate, as observed in the direction perpendicular or substantially perpendicular to the major surface, has four corners each having a notch with a side via electrode. By these side via electrodes, the mounting electrodes on one major surface are electrically connected to connecting electrodes, respectively, provided on the other major surface for connection to an external circuit board.
The electronic components described in Japanese Patent Laying-Open No. 2004-134430 and WO 2012/090986 have room for further reducing the audible sound generated by oscillation propagated from the multilayer ceramic capacitor to the external circuit board via the interposer.